This application claims the priority of German patent document 103 22 829.2, filed May 19, 2003 (PCT International Application No. PCT/EP2004/005009), the disclosure of which is expressly incorporated by reference herein.
The present invention relates to a control system for a vehicle, and in particular a combination of a towing vehicle and trailer.
German patent document DE 100 32 179 A1 discloses a generic vehicle control system in which the vehicle is equipped with an electronically actuable drive train that comprises at least one steering system, a brake system and a drive assembly. An operator control device which is permanently installed in the vehicle defines an input level via which a vehicle driver can input a driver request and which generates a standardized movement vector from the driver request. A second control device defines a coordination level which generates control signals based on an input movement vector, to actuate the drive train. To transmit the control signals, the second control device is coupled to the drive train, which then processes the control signals in order to implement the driver request.
The known control system is characterized by a high degree of variability, since input levels which are configured in different ways and coordination levels which are configured in different ways can easily be combined with one another, provided that the driver request is always converted into the control signals by means of the standardized movement vectors.
In utility vehicles (for example trucks), it is necessary to provide a person to give directions (sometimes referred to as a ground guide) for maneuvering during backward travel, in order to reduce the risk of collision between the vehicle and an obstacle. Furthermore, the maneuvering, and especially the backward travel is particularly difficult in the case of a combination of a towing vehicle and trailer, due to the given kinematic coupling.
The requirement for a person to give directions is extremely disruptive in the case of a truck from an economic point of view, since when the truck is in operation it mainly fulfills a transportation function in which there is no need for a person to give directions. In comparison, maneuvering is carried out only for a very short part of its operating time, and there is therefore an incentive to eliminate the necessity for a person to give directions.
One object of the present invention is to provide a control system of the type mentioned above, which simplifies the maneuvering of the vehicle.
This and other objects and advantages are achieved by the control system according to the invention, which is based on the general idea of using a path computer to calculate a movement path. The path computer provides a sequence of movement vectors which, when processed, move the vehicle from a starting position to a destination position. The starting position can be defined here by actual values for the current orientation and position of the vehicle, determined using a suitable orientation- and position-determining device. For the destination position, setpoint values for the orientation and position of the vehicle are used which can be predefined using a destination-inputting device.
The path computer transmits the acquired movement vectors to the second control device via the same drive train interface by which the operator control device, which is fixed to the vehicle, also transmits the movement vectors to the second control device. In calculating the movement path, the path computer can take into account the kinematic and dynamic properties of the vehicle. This is achieved by guiding the vehicle along an optimum (in particular risk-free) movement path. The maneuvering of the vehicle can be automated by predefining the setpoint values, and by monitoring the actual values and can be considerably simplified for the driver. Significantly, a person to give directions can be dispensed with.
In one advantageous development, the path computer is designed to calculate such a movement path in which the vehicle is traveling backward or which contains at least one movement path section in which the vehicle travels backward. This embodiment is particularly advantageous for a combination of a towing vehicle (sometimes referred to as tractor) and a trailer, since the backward travel of a combination is difficult and time-consuming even for experienced drivers. By calculating the backward travel and processing the necessary movement vectors, it is possible for the vehicle generally to reach the desired destination position at the first attempt with the control system according to the invention.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.